*{margin: 0; padding: 0;}
body{
  background-color: rgb(241,242,246);
  .fl{
    float: left;
  }
  .fr{
    float: right;
  }
  .clear:after{
    content: '';
    height: 0;
    display: block;
    clear: both;
  }
  .mt{
    margin-top: 20px;
  }
  .mb{
    margin-bottom: 20px;
  }
  .ml{
    margin-left: 20px;
  }
  .mr{
    margin-right: 20px;
  }
  ::-webkit-scrollbar {
    display: none;
  }
}
